Piston lubrication for internal-combustion engines.



G. F. WHEELER.

PISTON LUBRICATION FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED SEPT. 30. I9l2.

1 ,1 98,497. Patented Sept. 19, 1916.

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GEORGE E. WHEELER, OIE ERIE, PENNSYLVANIA.

PISTON LUBRICATION FOR'INTERNAL-QOMBU-STION ENGINES.

Specification of Letters Patent.

Patented Sept. 19, 1916.

Original application filed July 20, 1911, Serial No. 639,527. Divided and this application filed September To all whom it may concern:

Be it known that I, GEORGE F. WHEELER, a citizen of the United States, residing at Erie, in the county of Erie, State of Pennsylvania, have made a certain new and useful Invention in Piston Lubrication for Internal-Combustion Engines, of which the following is a specification.

This invention relates to piston lubrication for internal combustion or other engines; and contains subject matter divided out of my co-pending application Serial No. 639,527, filed July 20, 1911.

The object of the invention is to provide means which are simple in construction and efficient in operation, for lubricating the pistons of internal combustion or other engines.

The invention consists substantially in the construction, combination, location and relative arrangement of parts, all as will be more fully hereinafter set forth, as shown in the accompanying drawings, and finally pointed out in the appended claims.

Referring to the accompanying drawing, and to the various views and reference signs appearing thereon,-Figure 1 is a View in vertical central section of an internal combustion engine showing the application thereto of a piston lubricating arrangement embodying the principles of my invention. Fig. 2 is a broken detail view in section on a larger scale than Fig. 1, showing the water or water and oil lubricant feed. Fig. 3 is a similar view on the line 3, 3, rig. 2. Fig. 4: is a broken view in section showing a modified construction of piston.

The same part is designated by the same reference sign wherever it occurs throughout the several views.

The losses resulting from the operation of internal combustion and other engines due to the heat generated therein being carried off in the exhaust gases and through the water jackets employed, without performing useful work, is one important cause of failure of such engines to attain a desired degree of efliciency.

It is among the special purposes of my present invention to avoid loss of eficiency Serial N 0. 723,102.

from these sources by supplying water to the interior ofthe cylinder in order to absorb the heat and utilizing the water, so supplied, not only for heat absorbing purposes but also to form steam to aid in drivmg the piston, and to lubricate the piston.

In carrying out my invention I propose to employ a loose fitting piston, that is, a piston having a loose fit within the power cylinder, and to supply the lubricant, in the form of water or water mixed with oil, to the space between the exterior surface of the piston and the interior wall or surface of the cylinder, and in sufficient quantity to form in effect a floating piston. That is, I propose to surround the greater portion or substantially the entire surface of the piston, during its reciprocations within the cylinder with a film of lubricant, either water or water and oil, both being intended to be included by me in the use of the term lubricant, thereby not only efficiently lubricating the piston but also maintaining the piston as well as the inner surface of the cylinder cool. Where water is supplied as the lubricant it not only serves the purpose of a lubricant for the piston and a cooling medium for the interior of the cylinder, but it also is converted into steam and is utilized in that form to combine with the explosive charge, and to aid with its expansive action, in driving the piston.

In the drawings, B is the power cylinder; A the cylinder head or dome forming the explosion chamber; C an air box; L the piston; K the piston rod suitably connected in the ordinary or any desired manner to the crank of the main shaft; and b, the fly or balance wheel.

The cylinder B is mounted upon a casing which forms the air box G, into which air is drawn and compressed during the working operation of the piston, and from which the compressed air is led through a transfer box Y, to and delivered into the cylinder B through port 26, which is controlled by thepiston L, for the purpose of first scavenging the cylinder after each explosion'of charge therein, and then being compressed in the cylinder to form part of the next explosive charge. The transfer box Y, communicates with the interior of the cylinder at a point in front of the piston when the latter is in its limit of instroke. At a point substantially opposite the air inlet port 26 is the exhaust port 27.

In the form shown in Fig. 1, the piston is provided at suitable points on its periphery with circumferential packing rings M, spaced apart to leave the channels or spaces 64, therebetween, constituting chambers be tween the exterior surface of the piston and the interior surface of the cylinder, and into these chambers or channels water is supplied so as to entirely encircle the piston, thereby making the piston a floating piston, so to speak, the greater portion of the bearing surface between the piston and the cylinder being a water bearing, the surface of the rings M, being the only wearing surfaces. In practice I propose to employ a sufficient number of packing rings to prevent the piston surface from coming in contact with the inner surface of the cylinder. Then the circumferential chambers Get, are filled with a lubricant, as above noted, a seal is formed between the piston and cylinder surfaces, thereby preventing the escape of air compressed into the cylinder or of the gas produced by the explosions of the charges within the cylinder. It is obvious that the same results may be accomplished, and the same benefits and advantages attained, of a loose fitting piston, and the lubrication thereof together with the feature of the seal referred to, by cutting chambers into the exterior surface of the piston, as indicated at 110, Fig. 4, and making the exterior of the piston surface immediately adjacent and on opposite sides of each circumferential chamber con form closely to the bore of the cylinder.

In supplying the lubricant t0 the space between the exterior surface of the piston and the interior surface of the cylinder, it is necessary and desirable to provide means for balancing the lubricant, so supplied, against pressure of air, in the air box, or in the transfer box Y, which pressure is communicated through the inlet port 26, to those portions of the piston which are exposed to the air pressure as the piston moves past said port. In practice I prefer to locate the supply connection for the lubricant in close proximity to the air inlet port 26, and this increases the importance of securing the bal ance of pressures above referred to. The presence of any air pressure from the transfer passage Y, in the lubricant supply connection to the cylinder, would tend to form a trap for the lubricant and prevent the same from freely flowing into the circumferential chambers of the piston. To prevent this I provide means for balancing this air pressure thereby avoiding or breaking any trap that might otherwise be formed, and hence thereby insuring and securing the free flow of the lubricant to the piston surface.

IVhile I have shown, and will now describe a construction and arrangement embodying my invention for accomplishing the objects and purposes stated, I wish it to be understood that my invention, in its broadest scope as defined in the claims, is not to be limited or restricted in these respects nor to the particular construction shown, as other arrangements might be employed for supplying the lubricant to the chambers around the piston without danger of the compressed air gaining access to the lubricant supply connections. l/Vhere the an rangement shown in the drawings is employed however and in order to make the air balance doubly secure, compressed air is supplied from the transfer passage Y, or the port 26, to the sight feed valve or other lubricant supply connection, and also to afford means for equalizing the pressure on opposite sides of the lubricant supply. As a form of means for accomplishing this purpose I have shown a hollow yoke-shaped casting 7 see Fig. 2, to one end of which is attached a sight-feed water valve 5, through which water is supplied from any convenient source through supply pipe 9, or other suitable connection. A hand valve 111, may serve to regulate the flow of water through the sight feed valve. To the other end of yoke 7 is attached a sight-feed pressure oil cup 4. The yoke 7 is secured by means of a plug or other convenient form of connection, into an opening 113, which extends through the wall of the cylinder, and delivers to the interior of the cylinder. A pipe section 114, extends longitudinally through the passage 113 and to within a short distance of the inner wall surface of the cylinder, the other end of the pipe extending into and communicating with the interior of yoke 7. Through this pipe 114, the lubricant is supplied to the interior of the cylinder and upon the exterior surface of the piston as it moves past the delivery end of the opening or passage 113. It will be observed that the pipe 114, hangs within the chamber of passage 113, said passage or channel being of larger transverse area than that of the pipe 114. Extending vertically above the center of yoke 7, is a short stand-pipe 11, which is constructed with an air passage or duct 115 around the yoke 7. Through this duct or passage the stand-pipe is in free communication with the chamber or channel 113, and receives air from the transfer air-box port 26, and channel or passage 118. The standpipe 11, is also provided with openings to receive pipes 116, 117, connecting respectively with the water and oil supply connections. Also communicating with the stand-pipe 11, is a pipe connection 8, direct from the transfer box Y. By reason of this arrangement the air coming from the cylinder into the passage or channel 113, and the air coming from the air box direct to the standpipe will always equalize or balance each other, and this balance is maintained in the lubricating supply connections.

Itwill be observed that the supply of lubricant to the piston surface as above explained is accomplished continuously and uniformly and under conditions of a con stant head or pressure. I also propose in one embodiment of my invention, as shown to so locate the lubricant supply port or opening to the cylinder as to have the same constantly covered by the piston, thereby avoiding the danger of too great a flow of the lubricant to the cylinder.

From the foregoing description it will be seen that a supply of lubricating material is furnished to the exterior surface of the piston at a point closely adjacent its forward or front end, when at the inner limit of its stroke, so that as the piston moves forwardly in its outer stroke, it carries with it the surrounding films or jackets of lubricating material, water, or water and oil, which are carried in contact with the interior surface of the cylinder, thereby efliciently' lubricating the same, while at the same time an eflicient seal is formed by the lubricant between the exterior surface of the loose fitting piston and the interior surface of the cylinder, which prevents leakage or loss of air or of the gases of combustion from the cylinder. This enables me to employ a loose fitting piston and consequently to avoid the wear and friction incident to bearing contact of the piston with the interior surface of the cylinder. The lubricant prevents the packing rings from being cut, and the amount of lubricant required is greatly reduced, as compared with the amount ordinarily required in engines of this type and character.

The application of the lubricant in a thin film or sheet over the interior surface of the cylinder at each reciprocation of the piston effects an absorption of the internal heat developed by the explosions of the charges in the cylinder, and hence I am enabled to construct engines of very large size and capacity without danger of developing undue heat therein. The supply of lubricant, as above explained also furnishes a source for the generation of steam within the cylinder which combines with the explosive charge to increase the efiectiveness thereof, and which also is superheated and adds its expansive force to that of the explosion of the charge in driving the piston. The presence of the steam in the explosion chamber and its expansion along with the products of the explosion causes the gases to burn slowly and consequently a more perfect and complete combustion of the gases takes place, thereby avoiding the deposit of unconsumed particles of carbon on the interior surface of the cylinder. The steam, also, by absorbing the heat resulting from the explosions cause the gases of the explosion to be liberated or exhausted from the cylinder at a lower temperature than would otherwise be the case, thus greatly adding to the economy and efliciency of the engine.

In practice I prefer to employ large quantities of water in the peripheral channels or chambers of the piston, where water is used, and I have found an arrangement such as above described exceedingly simple and efficient in preventing carbon deposits on the piston, or on the interior walls or surfaces of the cylinder, thus entirely eliminating and overcoming the greatest troubles heretofore experienced in engines employing heavy hydro-carbon oils, and permitting the use of the cheaper grades of oil as the fuel element for the explosive charges.

By eliminating to a large extent the internal heat of the engine through the use of a lubricant as above explained, and its performance within the cylinder, I not only turn to advantageous use the internal heat developed in the cylinder, and which has heretofore been a source of waste, but I also decrease the amount of jacket cooling water required, thereby largely eliminating one of the most serious sources of loss in internal combustion engines.

Having now set forth the objects and na ture of my invention, and a construction embodying the principles thereof, and having explained such construction, its purposes, functions and mode of operation, what I claim as new and useful, and of my own invention, and desire to secure by Letters Patent is: Y

1. In an internal combustion engine, a cylinder, a loose fitting piston operating in said cylinder, said cylinder having an opening through the side wall thereof and within the limit of the stroke of the piston in either direction, a lubricant supply delivering to said opening and means for counterbalancing the effect of the internal pressure wlithin the cylinder upon the lubricant sup- P y- 2. In an internal combustion engine, a cylinder having an opening and an airsupply port, a loose fitting piston operating in the cylinder, past said opening and lubricant supply connections delivering to said opening, a compressed air connection delivering to said port, and connections whereby the trapping of the lubricant supply by the internal engine pressure is prevented.

8. In an internal combustion engine, a

and an air pressure supply port, a loose fit- 'In testimony whereof I'have hereunto set ting piston operating in said cylinder to my hand in the presence of the subscribing 10 constantly cut of? the lubricant supply open- Witnesses, on this 21 day of Sept. A. D., ing, lubricant supply connections deliver- 1912.

, ing to said opening, and means to counter- GEORGE F. WHEELER.

balance the air pressure supply acting Witnesses: through said port and opening upon the. LOUIS GALMISH, lubricant feed. LEONARD H. WHEELER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 

